In reality, the process which has yielded our contemporary understanding of the human brain is not a linear progression of ideas; but a gradual refinement of questions.  For what distinguishes our understanding from that of our intellectual forbearers is not its relative correctness, its value to humanity, nor the degree to which it may be judged objective and complete; but rather, simply the relative breadth of the questions from which it has been derived.

The world known to the scientists of Ancient Greece did not include neurons, neurotransmitters, or hormones (except, perhaps, as ideas); and as such, knowledge of these structures is not reflected in those questions they posed, and considered, in their attempts to understand themselves and the world they occupied.  Contemporary scientists, being now aware that such structures exist (an awareness extended by the innovation of engineers), are afforded, by this awareness, the privilege to pose questions which narrowly focus their efforts upon these minute aspects of their world; and, thereby, the ability to seek understanding of themselves, and their world, in regions unimagined - and for this reason alone unexplored - by their predecessors.

Despite this apparent difference, however, the ultimate understanding contemporary scientists seek, remains fundamentally the same as that sought by their intellectual forbearers in Ancient Greece.  For the cradle of all scientific inquiry is the human experience, and thus, those mundane mysteries it alone has long cast, unprejudiced, upon man's curiosity and intellect - among these: the mysteries of consciousness, illness, death, and motion.

That contemporary scientists no longer ask “what is the 'self'?”, then, should not suggest to us that the answer to this question is no longer sought; but rather, that it is sought within other questions - questions such as “how is language processed?” or “where is the sensation of pain experienced?”  Though neither of these questions, alone, attempts to glean understanding regarding the entire nature of the 'self'; each examines a specific quality of this seemingly intangible aspect of our existence that may, when considered collectively, yield insight into the larger question from which they are derived (“what is the 'self'?”).

Consider, for example, how mankind has approached the study of illness.

Throughout human history, man has been confronted by a plethora of physical ailments that, to the extent to which any two cultures occupied similar geographic and environmental regions, would have exhibited themselves in an accordingly similar manner - the physical manifestation of a fever, for example, would have been largely identical whether the individual afflicted resided in equatorial Africa, southern China, central Mexico, or northern India.  Yet, the manner by which the peoples occupying each of these lands considered this ailment, and the techniques they employed in its treatment, varied considerably depending upon the theoretical foundations of their respective cultural traditions.

In describing the ideas held by the the Mano - a people who currently occupy the northern tip of the Republic of Liberia; US physician and missionary George Way Harley (1894-1966), in his 1970 text Native African Medicine, wrote that “the Mano man believes that everything animate or inanimate has a sort of spirit or power within it [...] To him the struggle for existence between all creatures, including plants and even stones, is a very real struggle, each individual holding its place by some innate strength of personality.  Many of these personalities are to him highly admirable and useful [...] He knows [...] a certain fruit of a vine which acts as a powerful heart stimulant.  He eats this for endurance.  To us the fruit is not magic, it is therapeutic.  But leaf, stone, and fruit are all the same to him; in each case he has caught the spirit of the substance and used it to his own good.”

“These forces, Yin and Yang, are theoretically supposed to balance each other completely but are, in reality, in a constant state of conquest and defeat, of ebb and flow, as it is expressed in the nature in the change from day to night.  Within the body, too, the distribution of the two elemental forces is uneven [...] The complicated relationship of the dual power with the various parts of the body can function smoothly only if the flux of Yin and Yang is uninterrupted.  When there is stagnation in certain parts of the body and hence a deficiency in others, the result is disease.  The twelve ducts are supposed carriers of the two cosmic forces, and if stagnation occurs it takes place within these channels.  It is thought that by puncturing the channels at those points which are connected with the diseased organ, the evil air that caused the stagnation is forced to escape and circulation can set in again.”

According to the description presented by US medical historian Gordon Allen Schendel (1905-1982), in his 1968 text Medicine in Mexico: From Aztec Herbs to Betatrons, the Aztecs - a composite people who once occupied lands located in present-day central Mexico; “individual gods and goddesses were believed to have the dual power to both cause and cure certain diseases, at will - and often were linked to specific herbs and other remedies.  Thus the Aztec physician's treatment of illness frequently had to take into account the role of the relevant deity.”

In the introduction to his 1963 translation of the Sushruta Samhithā, a text believed to have been composed by the Vishvámitran physician Sushruta (c. 6th Century BC); Indian translator Kaviraj Kunja Lal Bhishagratna (1865-?) describes human illness as brought about by the imbalance between an individual's bodily humors - referred to as Váyu, Pittam, and Kaphah.  These “are called Dhótus or fundamental principles of the economy, when in virtue of their correlative and sustentative functions, or with the help of their subservient processes of metabolism and lymphatic circulation, they ensure and equipoise among the different vital and physiological processes in the whole economy which is essential to its perfect health.  Biologically considered they are but the primary subtle dynamics of organic life, or [...] the three fundamental principles of the body.  But when this healthy equilibrium is disturbed either through the agency of an extrinsic or idiopathic factor, when any other of them is abnormally augmented or dominates the other two, thus altering their mutual relation in the economy, naturally certain pathological conditions arise which form the esse of a disease.”

Each of these treatment practices was founded upon a unique underlying theory, and while it may be tempting to believe that those which we practice today are not; in reality, they differ from those described above only in the nature of their underlying theory.

The Mano physician treated illness with herbal remedies believing that by doing so, the spirit contained within each substance would relieve the suffering of the afflicted individual.  The Ancient Chinese physician treated illness with techniques such as moxibustion and acupuncture believing that any physical ailment was brought about by an imbalance in the individual's Yin and Yang resulting from a disruption in their circulation; and that only by returning this circulation to its uninterrupted state, could the health of the individual be returned.  The Aztec physician treated illness by applying herbal remedies with the belief that each herb invoked the power of a different supernatural being, and that only by invoking the proper deity, and appealing for their grace, could the exhibited symptoms be alleviated.  The Vishvámitran physician treated illness believing that such infirmities were brought about by an imbalance between the individual's bodily Doshas; and that only by returning these qualities to their original proportions, could the individual be returned to his prior condition.

Contemporary physicians - who practice what has been termed experimental, or scientific, medicine; treat  illness based upon the emerging understanding of the biological and physiological properties of their contributing agents - whether these be acquired (e.g. germs), or ingrained (e.g. genetic characteristics); the belief that the human body, as a physical system, is subjected to the same material rules that govern all of nature; and that, as a product of evolution, this system is one shaped by those processes serving natural selection.

While this underlying theory has allowed contemporary physicians to refine, considerably, the manner by which they may otherwise approach the treatment of certain illnesses; understanding the causal relationship between these agents, and the illnesses with which they are associated, continues - as it did their forbearers - to elude them.  Not every individual who has been bitten by a malaria-carrying mosquito will develop this illness; and not every individual who develops this illness will experience it, or respond to a specific form of treatment, in the same manner.  Not every individual possessing genes believed to be associated with the development of cancer will develop this illness, and not every individual without them will be spared from its development.

Scientific inquiry, if we attempt to define this term in as accurate a manner as possible; is a pursuit for knowledge founded upon the belief that past experience and understanding may provide insight, and possibly the ability to predict, future outcomes and events.

We refer to the rules by which this knowledge is applied, today, as logic and reason - and those rules applied by our intellectual forbearers as magic and superstition.  Yet, just as each individual may be said to possess a different world-view depending on their unique experiences; each human society (irrespective of its relative historical position) has held its own view regarding the world that they occupied, and these views varied based upon the aspects of the world that they could explore; and the manner by which they chose to interpret what they had seen.  While one view may appear to us magic, and the other science; each is founded upon the same underlying theory - that past experience and understanding can provide insight into future events.

That this process is founded upon culture, then, is most easily demonstrated if we observe that none of the underlying theories described above was incomplete.  An Aztec physician would not abstain from treating an illness simply because it was one that he did not recognize; or deny the occurrence of an event simply because it did not conform with his prior understanding and experience.  Instead, he would likely attempt to apply ideas and understanding garnered from similar observations (whether his own, or acquired thru tradition) to comprehend those that have departed from them.  In speculating upon the origins of the healing arts within the Mashona tribe of present-day Zimbabwe and southern Mozambique (then Rhodesia), South African physician Michael Gelfand (1912-1985), in his 1956 text Medicine and Magic of the Mashona, wrote that:

Presently, there exists a vast body of natural phenomena that continue to elude contemporary scientific understanding (e.g. the placebo effect); and until these have all yielded their secrets to those techniques man applies in conducting his scientific inquiries; scientific understanding will remain a product of human culture, and the success and longevity of a given treatment practice, dependent upon only one factor - whether or not the afflicted individual continues to suffer from their symptoms following treatment (and if so, to what extent their symptoms remain unaffected).

If a treatment technique, founded in contemporary scientific understanding, fails to elicit an alleviation of these symptoms (or produces a worsening of the afflicted individual's condition), its practice would not be prolonged solely because its theory is a logical extension of its practitioner's scientific understanding.  Similarly, if a treatment technique proves successful in either the elimination, or lessening, of these symptoms; its continued practice would not be inhibited by whether its practitioners understood the microscopic nature of the illness, the chemical nature of the substances used in its treatment, or the nature of the interaction between the illness-contributing agent and the physical systems of the affected individual.

Consider, for example, the narrative by Japanese physician Genpaku Sugita (1733-1817), transcribed in his 1815 text Rangaku Kotohajime (translated: Dawn of Western Science in Japan), of how Dutch ideas regarding anatomy and physiology were first introduced to Japan during the latter years of the eighteenth century; and the description by Sri Lankan historian Laxman Devasena (Dates Unknown), in his 1981 thesis Some Traditional Sri Lankan Medical Techniques Related to Acupuncture, of the continued survival of traditional (holistic) medical practices alongside those of contemporary (experimental) medicine.

The questions we must ask, if we are to glean a true insight into our contemporary understanding of the human brain, thus, are not “what do we understand?”; but those questions which must occupy the foremost position within the mind of the scientific researcher - namely, “how have we understood what we have observed, and why have we interpreted our observations in the manner we have?”

Within the introductory discussions that will follow this preface, we shall examine the motivations that may have provided the impetus for man to engage in his inquiries toward understanding his world, as well as those processes that have served to both develop and refine his acquired understanding.  Before we proceed, however, in the interest of clarity and simplicity; we shall first pause to define the terms scientist, philosopher, and engineer in the manner in which they shall be referred to herein.

To consider scientists solely as those individuals who rely upon the experimental method as it appears today, would be akin to considering actors solely as those individuals who have performed in motion pictures - thereby excluding all those who have dedicated their careers to radio or stage productions.  In the interest of avoiding such restrictive definitions, we shall instead define scientists as those individuals who ascribe to the belief that previous experience and understanding may be applied to comprehend and predict future events, and who apply this belief in attempting to understand those events which transpire between an individual's birth and death; philosophers as those who ascribe to this same belief, but extend its application to events beyond birth and death; and engineers as those who apply understanding garnered by observation in the design of tools and other artificial devices that extend both man's ability to study his world, and his ability to manipulate it.